Apparatus for floating and finishing soft concrete



Jan. 6, 1953 v c. BIRD 2,624,250

APPARATUS FOR FLOATING AND FINISHING SOFT CONCRETE Patented Jan. 6, 1953 UNITED STATES PATENT OFFICE APPARATU sy FOR FLOATG ANU vFiNIsInNGsvoF'r CONCRETE charles Bird, Dayton, om@ Application Februar-y 14,1950, vSerial No.1`4'4,12`2

6 Claims.

This invention relates to an apparatusfor distributing and leveling softconcrete and more particularly to such an apparatus adapted to besupported above and moved overv the concrete which isto be distributed',and comprising'a plurality of individual rotatable elements fordistributing and leveling the concrete and providingY the same with afinished surface.

It has been proposed heertofore to provide an apparatus of thisV generaltype but these prior apparatus have been unsatisfactory and so far as'Il am informed none of them have gone into commercial use'.

One object of the invention is tov provide such an apparatus having aplurality of rotatable elements for floating the concrete vand soarranged that the concrete will be leveled and all markings or roughportions on the surface removed.

A further object of the invention is to provide such an apparatus' inwhich the floating elements will be of such a character and! sovarranged that the path of rotation of each element will overlap aportion of the path of rotation of an adjacent element, or elements.

A further object of the invention is to providesuch an apparatus havinga plurality of seriesof rotatable elements so arranged that'the elementsof each series will move ex'ce'ss'material lengthwise of that series anda second series of elements will move that excess material to the edgeof the pavement.

A further object of the invention-is to provide a floating element ofimproved construction for operation in the manner described.-

Other objects of the invention may appear as the apparatus is describedin detail.

In the accompanying drawings, Fig. 1 is a plan view of an apparatusembodying the invention; Fig. 2 is a side elevation of such anapparatus; Fig. 3 is a section taken on the line 3-3 of Fig. l; and Fig.4 is a sectional detail view of one of the floating elements.

In these drawings I have illustrated one embodiment of the invention butthis embodiment has been chosen for the purpose of illustration only andit is to be understood that the apparatus as a whole, as well as theseveral parts thereof, may take various forms and arrangements withoutdeparting from the spirit of the invention.

In the embodiment here illustrated the apparatus comprises a movableframe including three longitudinal bars 5, parallel with the line ofmovement of the frame, and a plurality of transverse cross bars 6rigidly connected with the` longitudinal bars and spaced one from theother. The outerlongitudinal bars B'arejsupported by rollers' T adaptedto engage and to travel on the upper edges of the longitudinal forms, orbars, wh'i'ch corinne the concrete and determine the'width of thesection of pavement being laid. The rollers are preferably grooved toembrace the upper edges of the bars 8 and prevent the lateraldisplacement of the apparatus;

Mounted on the frame is a series, or a plurality of series,` ofrotatable elements 9` arranged to engage the cement, distribute andlevel the same and provide the 'leveled cement with a finished surface,these elements being herein referred to as floating elements.` Eachnoating element is individually rotatable about a vertical axis. Thefloating elements of each series are mounted on a rigid structure, suchas one of the cross bars 6', and constitute what is commonly called ascreed. There may be any suitable number of screeds and in thepresentinstance, there are four screeds which are preferably arranged in pairs,and the screeds of each pair are preferably arranged in a linetransverse to the line of movementl of the frame. The screeds of thefrontpair of screeds are designatedv as A and A', the' two screeds beingarranged on opposite sides off thel'ong'itudinal center line oftheframe. The screeds of the rear pair'of screeds are designated as B' andB', and are also arranged on opposite sides ofthe center line of thelframe. The floating elementsof each screed rotate in the same direction.and the floating elements of the screeds of-"each-E pair rotate inopposite directions. Preferably the floating relements of the twoscreeds on the same kside-of the center line rotate in oppositedirections. Thus, the floating elements of screed. A rotate`counterclockwise and the floating elementsfof'A rotate clockwise andthe-oating elements of screed B rotate clockwise and thefloatingnelernents of screed B rotate counterclockwise.

The floating elements ofl each screed are of such a character andaremounted for rotation about vertical axes so arranged that each elementmay make a complete rotation about its axis without contacting orinterfering with the rotation of an adjacent element. For this purposeeach noating element is mounted for rotation about an ofi-center axisand as here shown, each oating element is rigidly. connected, adjacentone end thereof, with a shaft l0 which isrotatably mounted in a verticalbearing I'l on the supporting structure and is provided above thebearing means with means whereby it may be drivngly connected with asuitable source of a 3 power, such as an internal mounted on the frame.The floating elements may be of any suitable shape and preferably eachsuch element comprises an oblong or elongate body which decreases inwidth from one end thereof to the other end thereof. Each floatingelement is rigidly secured to its shaft I and the several shafts are soconnected one with the other, as will appear hereinafter, that thefloating elements of each screed extend at all times in the same radialdirection from their respective shafts. from the other that the outer orlarger end of each element will pass the inner or smaller end of theadjacent element, or elements, but will move close to that element, andthus, the path of rotation of each element intersects or overlaps aportion of the path of rotation of an adjacent element, or elements. Thedistancebetween shafts as measured in the transverse direction isslightly greater than the distance between the two spaced centers oraxes on the rotatable element 9 plus the radii of the element at thesmaller and larger ends. The elements, therefore, have an overall lengthwhich is slightly less than the distance between the shafts.Consequently, as each element rotates, the larger end of the elementwill describe a path about the axis of the smaller end, and has anoutermost boundary which does not quite touch the radial surface of thesmaller end of the adjacent element.

In the particular form here shown, the two ends of each floating elementare approximately semi-circular but of different diameters and thelateral edges of the body converge toward the smaller end thereof. Theshaft is connected with the body at a point between the smaller endthereof and the transverse center line of the body. Preferably the bodyof the floating element has a flat lower surface and is provided with acontinuous upwardly extending flange I3, the edges of the body beingrounded. While the shafts are here shown as connected with the body ofthe floating element adjacent the smaller end thereof, this shaft may beconnected with either end portion of the body and will function insubstantially the same manner when connected at either point, andpreferably each floating element is provided with means whereby theshaft may be detachably connected with either end portion thereof.Y Inthe present instance, as best shown in 1Eig. 4, the body of each elementis provided with two upwardly extending socket members, or bosses, I4,arranged adjacent the respective ends thereof, each boss having meanswhereby the shaft may be connected therewith. In the particularvarrangement shown, the lower end of the shaft is adapted to fit snuglywithin either boss, the shaft is provided with a flange I to engage theupper end of the boss and this flange is provided with openings toreceive screws IB by which it may be detachably secured to the boss.

Movement is imparted to the frame by the motor I2 which is drivinglyconnected with a part of the rollers "I, as shown schematically at I'Iin Fig. 2. The motor may be connected with the floating elements of theseveral screeds in any'suitable manner. In the present arrangement thereare provided two vertical shafts I3 and I9 which are connected in aconventional manner with the motor for rotation thereby in oppositedirections. The shaft IB is connected by a sprocket chain with the shaftI0 of the combustion motor I2 The shafts are so spaced one innerfloating element of screed B and the shafts of the several floatingelements of that screed are connected one with the other by sprocketchains 2|, 22 and 23, as shown in Figs. 2 and 3. The shaft I9 of theinner floating element of screed B is connected by a sprocket chain 24with the shaft I@ of the inner floating element of the screed A. Thevertical shaft I9 is connected by a sprocket chain 2'5 with the shaft IUof the inner floating element of screed B and that shaft is connected bya sprocket chain 26 with the shaft of the inner floating element ofscreed A, the several shafts of each screed being connected one with theother in the same manner as the shafts of screed B,

As the apparatus moves forwardly over the soft freshly laid concrete thefloating elements of screed A', rotating in a clockwise direction, willdistribute the concrete, level the same and move excess concretetransversely to the line of movement of the apparatus, and the excessconcrete advanced by each floating element is engaged and furtheradvanced by each succeeding floating element of that screed. The innerfloating elements of the two screeds of the front pair A and A' alsomove in overlapping paths and any excess material advanced by the innerfloating element of screed A will be engaged and advanced by the innerfloating element of screed A and the other elements of that screed will-move excess material, if any, to and beyond the edge of the pavement.Inasmuch as each floating element of each screed moves over the adjacentportion of the path of rotation of the next preceding floating elementit will remove any markings or rough places which may` have remainedafter the preceding screed has moved over the material. Y It will beunderstood that the floating elements rotate at relatively high speedwhile the apparatus as a whole moves forward at a low speed, thus eachfloating element moves repeatedly over the same part of the concrete asthe apparatus slowly advances. The floating elements of the rear screedsB and B function in the same manner as the floating elements oftherfront screeds but the floating elements ofthe rear screeds rotate indirections opposite to the directions of rotation of the floatingelements of the corresponding front screeds, and serve to eliminate anyroughness and to fill any depressions which may have been left onor inthe surface of the concrete levelled by the front oating elements, thusproviding the pavement with a properly finished surface. The apparatusmay move in either direction and usually moves forwardly and thenrearwardly over each section of pavement and may make several passesover each section. When the apparatus moves in the reverse direction therear screeds become the front screeds but the operation is the same aswhen the apparatus moves forwardly.

Due to the operation of the motor and the movement of the apparatus, aslight vertical vibration is imparted to the several floating elementswhich causes the aggregate of the concrete to settle more or less,thereby leaving the fines in the upper portion of the concrete andavoiding' the presence of pebbles or the like in the nished surface.

While I have shown and described one embodi- I do not desire to belimited to the details thereof l tion, what I claim as new and usefuland desire to secure by Letters Patent, is:

1. In an apparatus for floating and finishing soft concreter, a movableframe, a screed mounted on said frame and extending transversely to theline of movement thereof, said screed comprising a plurality of oblongfloating elements, means for mounting each of said elements on a partxed with relation to said frame for rotation about a vertical axisextending through an end portion of said element, the several axes beingspaced one from the other lengthwise of said screed distancesapproximating the length of each element, and means for rotating saidelements in unison and in the same direction.

2. In an apparatus for floating and finishing concrete, a movable frame,a screed on said frame extending transversely to the line of movementthereof, said screed comprising a plurality o oblong floating elements,each element decreasing in width toward one end thereof, means formounting each of said elements on a part fixed with relation to saidframe for rotation about a vertical axis extending through an endportion of said element, the several axes being spaced one from theother lengthwise of said series at distances approximating the length ofsaid elements whereby the elements may move into longitudinal alinementwithout interference with adjacent elements, and means for rotating saidelements in unison and in the same direction.

3. In an apparatus for floating and finishing concrete, a movable frame,a screed on said frame extending transversely to the line of movementthereof, said screed comprising a plurality of oblong floating elements,each element decreasing in width toward one end thereof and both endportions thereof being approximately semicircular, means for mountingeach of said elements on a part iixed with relation to said frame forrotation about a vertical axis extending through an end portion of saidelement, the several axes being spaced one from the other lengthwise ofsaid series at distances approximating the length of said elementswhereby the elements may move into longitudinal alinement withoutinterference with adjacent elements, and means for rotating saidelements in unison and in the same direction.

4. An apparatus for floating and finishing soft concrete comprising aframe having means whereby it may be supported above the concrete whichis to be oated and moved over the same, and a plurality of oatingelements rotatably mounted on said frame substantially in a common planeabout off-center axes arranged substantially in a line transverse to theline of movement of said frame, the axes about which'.

said oating elements rotate being spaced apart distances approximatingthe length of the elements whereby that part of each oating elementwhich is the farther removed from the axis or rotation thereof rotatesin a path which overlaps the path of rotation of the corresponding partof an adjacent floating element, and means for rotating said lloatingelements at the same speed.

5. An apparatus for oating and finishing soft concrete comprising aframe having means whereby it may be supported above the concrete whichis to be floated and moved over the same, two series or floatingelements mounted on said frame and extending transversely to the line ofmovement thereof on opposite sides of a line extending in the directionof movement of said frame, the elements of each series being rotatablein the same direction and in unison about vertical oi-center axes andthe elements of each series being rotatable in unison in a directionopposite the direction of rotation of the elements of the other series,and the axes of adjacent elements of the two series being spaced atdistances approximating the length of the elements, whereby the paths ofrotation of adjacent elements overlap, and means for rotating thefloating elements of both series.

6. An apparatus for iioating and iinishing soit concrete comprising aframe having means whereby it may be supported above the concrete whichis to be oated and moved over the same, a pair of front screeds and apair of rear screeds mounted on said frame, the screeds of each pairbeing mounted on opposite sides of a line extending in the direction ofmovement of said frame substantially in line one with another, eachscreed including a series of oating elements rotating in unison in thesame direction about oilcenter axes, the elements of the screeds of eachpair being rotatable in unison in opposite directions, and the elementsof the screeds on the same side of said line being rotatable in oppositedirections, and the axes of adjacent elements of each pair of screedsbeing spaced at distances approximating the length of the elementswhereby the path of rotation of each floating element on each screedhaving a radius of a length greater than one-half the distance betweenthe axes of adjacent oating elements on said screed whereby the paths ofrotation of adjacent elements overlap, and means for rotating thefloating elements on the several screeds.

CHARLES BIRD.

REFERENCES CTTED The following references are of record in the ille ofthis patent: f

UNITED STATES PATENTS Number Name Date 1,808,719 Giles June 2, 19311,828,576 Palatini Oct. 20, 1931

